Photon Focus MV2-D1280-640, User Manual, Page: 24 / 85

4 Functionality
Sequential readout
By default the camera continuously delivers images as quickly as possible ("Free-running
mode") in the sequential readout mode. Exposure time of the next image can only start if the
readout time of the current image is finished.
e x p o s u r e r e a d o u t
e x p o s u r e r e a d o u t
Figure 4.2: Timing in free-running sequential readout mode
When the acquisition of an image needs to be synchronised to an external event, an external
trigger can be used (refer to Section 4.6 and Section 5.4). In this mode, the camera is idle until
it gets a signal to capture an image.
e x p o s u r e r e a d o u t i d l e e x p o s u r e
e x t e r n a l t r i g g e r
Figure 4.3: Timing in triggered sequential readout mode
Simultaneous readout (interleave exposure)
To achieve the highest possible frame rates, the camera must be set to "Free-running mode"
with simultaneous readout. The camera continuously delivers images as quickly as possible.
Exposure time of the next image can start during the readout time of the current image.
e x p o s u r e n i d l e
i d l e
r e a d o u t n
e x p o s u r e n + 1
r e a d o u t n + 1
f r a m e t i m e
r e a d o u t n - 1
Figure 4.4: Timing in free-running simultaneous readout mode (readout time> exposure time)
e x p o s u r e n
i d l e r e a d o u t n
e x p o s u r e n + 1
f r a m e t i m e
r e a d o u t n - 1
i d l e
e x p o s u r e n - 1
Figure 4.5: Timing in free-running simultaneous readout mode (readout time< exposure time)
When the acquisition of an image needs to be synchronised to an external event, an external
trigger can be used (refer to Section 4.6 and Section 5.4). In this mode, the camera is idle until
it gets a signal to capture an image.
4.1.2 Exposure Control
The exposure time defines the period during which the image sensor integrates the incoming
light. Refer to Table 3.2 for the allowed exposure time range and see Section 5.4.1
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